PhET-Simulations-for-Chemistry/C3/Salts-and-Solubility/English

Salts and Solubility

Author: Snehalatha Kaliappan

Keywords: PhET Simulation, Salts, sparingly soluble salts, solubility, molar solubility, solubility product, molarity, Le Chaterlier’s principle, equilibrium expression, spoken tutorial, video tutorial.

Visual Cue	Narration
Slide Number 1 Title Slide	Welcome to this tutorial on Salts and Solubility
Slide Number 2 Learning Objectives	In this tutorial, we will learn about, Solubility of different salts. Create a neutral compound from anions and cations. Equilibrium expression for dissolution of salt in water.
Slide Number 3 Learning Objectives	Calculate the Molarity of solutions. Calculate Solubility Product of the salts. Application of Le Chaterlier’s principle to the dissolution of salts.
Slide Number 4 Learning Objectives	Design a salt with various combinations of charges and Solubility Products. Use Solubility Product values to predict solubility.
Slide Number 5 System Requirement	Here I am using, Windows 11 (64 bit) Java version 1.8
Slide Number 6 Pre-requisites https://spoken-tutorial.org	To follow this tutorial learner should be familiar with topics in high school science. Please use the link below to access the tutorials on PhET Simulations.
Slide Number 7 Link for PhET simulation Point to https://phet.colorado.edu/en/simulations/soluble-salts	Please use the given link to download the PhET simulation.
Point to the file in Downloads folder.	I have downloaded the Salts & Solubility simulation to my Downloads folder.
Double click the file to open	To open the simulation double-click on the file.
Cursor on the interface.	This is the interface of Salt and Solubility simulation.
Cursor moves across the tabs.	It has 3 tabs.
Cursor on Table Salt interface.	Table Salt opens first by default. The main panel shows a container with inlet and outlet water taps.
Show the location of inlet and outlet taps.	Inlet water tap is placed at the top-left of the container. Outlet water tap is placed at the bottom-left of the container.
Cursor on container.	The container is graduated and is filled with water. The markings show from 1x 10-23 Liters to 8x 10-23 Liters.
Drag the slider on the inlet water tap.	Drag the slider on the inlet water tap towards the right side to fill the container.
Drag the slider on the outlet water tap.	To drain the water from the container, drag the slider on the outlet water tap.
Show salt shaker.	A salt shaker is placed at the top of the container. Shake the salt dispenser to add salt to the container.
Cursor on right panel.	On the right panel you will see the Salt and Water sections.
Cursor on right panel.	Salt section gives information about the ions present in the container. It shows the number of Dissolved, Bound and Total number of ions in the container.
Cursor on right panel.	The Water section shows the volume of water in the container.
Cursor on Reset All button.	Click on the Reset All button on the right panel. To reset the simulation to the default parameters.
Cursor on the water container.	Let us see how table salt dissolves in water. Let the water level in the container be at the default level, 5x10-23 liters mark.
Shake the salt shaker.	Shake the salt shaker to add salt to the container.
Slide Number 8 Solubility Product Expression: Sodium Chloride	Table salt is scientifically called Sodium Chloride. It ionizes in water as Sodium and Chloride ions.
Slide Number 9 Solubility Product expression of NaCl NaCl(s) ⇄ Na+(aq) + Cl-(aq) [Na+] [Cl-] 1:1 [Na+]=S, [Cl-]=S Ksp [Na+] [Cl-] Solubility Product(sp)= SxS= S2	Here is the Solubility Product expression of Sodium Chloride.
Slide Number 10 Solubility Product expression of NaCl	The smaller the Solubility Product, the lower the solubility.
Cursor on sodium and chloride ions.	Sodium ions are represented as red spheres and chloride ions as green spheres.
Shake the salt dispenser.	Add more salt to the container and observe the solution.
Cursor on sodium and chloride ions.	As soon as the salt touches the water it dissociates into sodium ions and chloride ions.
Cursor on right panel.	Note the number of sodium and chloride ions in the Salt panel on the right. They are equal in number. The sodium chloride is neutral molecule. It has one positive sodium ion and one negative chloride ion.
Shake the salt dispenser. 87 ions in solution, no bound ions.	Add more salt to the container. Observe the right panel. Wait for a few seconds for the solution to reach equilibrium.
Cursor on the water container.	Sodium chloride is highly soluble in water. The bound ions will be zero until it reaches the saturation level.
Shake the salt dispenser.	Add more salt until you see some bound ions in the Salt panel.
Cursor on the right panel.	The salt solution has now reached saturation level. The bound or undissolved ions are in equilibrium with the dissolved ions in solution.
Cursor on the right panel. 180 dissolved ions.	Approximately 180 dissolved ions are observed. Notice the continuous adjustment of dissolved and bound ions on the panel.
Cursor on the water container.	Observe the ions in the container. The ions continuously go back and forth from dissolved to bound state to maintain the equilibrium.
Cursor on the right panel.	Molar solubility for sodium chloride can be calculated using the information in the right panel. Solubility Product can be calculated from the Molar Solubility value for each salt.
Cursor on the right panel.	Note the number of cations and anions at saturation state for Sodium Chloride. It is 180 in 5 x 10-23 liters for Sodium Chloride.
Slide Number 11 Calculations: Molar Solubility	This slide shows how to calculate Molar Solubility for Sodium Chloride.
Slide Number 12 Calculations: Solubility Product of NaCl	We can also calculate Solubility Product for sodium chloride using Molar solubility values.
Slide Number 13 Calculations: Solubility Product of NaCl	Please refer to the Additional reading material for details of calculations.
Cursor on Simulation interface.	Back to the simulation. Add more salt. The number of bound ions increases in the solution.
Drag the slider on the inlet tap.	Add some water to the container. Observe the ions in the panel as well as in the container.
Cursor on the simulation.	The number of dissolved ions increases with dilution. This is because the bound ions now dissolve in the extra added water. This is in accordance with Le Chatelier's principle.
Drag the slider on the inlet tap.	Add more water until all the bound ions are completely dissolved.
Cursor on the simulation.	Please refer to the Additional material link for more information on Le Chatelier's principle.
Click the Reset All button.	Click the Reset All button.
Narration only	Practice with a different volume of water in the container. Observe the results.
Click on Slightly Soluble Salts tab.	Next click on Slightly Soluble Salts tab. The right panel on the screen shows a drop-down in the Salt section.
Cursor on the right panel.	6 different types of sparingly soluble salts are listed here.
Cursor on the screen.	The rest of the simulation interface is similar to the Table Salt screen.
Point to the first salt in the list Shake the salt dispenser.	The first salt in the list is Strontium Phosphate. Shake the salt dispenser. A little amount of salt is added to the container with water.
Cursor on the right panel.	Notice the ratio of Strontium to Phosphate ions in the right panel.
Slide Number 14 Solubility Product expression for Strontium Phosphate.	This slide shows the Solubility Product expression for Strontium phosphate.
Slide Number 15 Solubility Product Expression: Srontium Phosphate	The stoichiometry is 3 is to 2 (3:2). Therefore the Strontium Phosphate molecule consists of: 3 atoms of Strontium and 2 units of Phosphate.
Shake the salt dispenser.	Shake the salt dispenser a few more times. You will now notice some bound Strontium and Phosphate ions in the container.
Observe the right panel.	Observe the right panel.
Shake the salt dispenser.	Shake the salt dispenser a few more times until you see constant unbound ions in solution.
Observe the right panel.	The solution is now saturated. The equilibrium is established. At this stage, 45 Strontium and 30 Phosphate ions are in dissolved state. The ratio is 3: 2
Observe the right panel.	Molar solubility for salts can be calculated using the information in the right panel. Solubility Product can be calculated from the Molar Solubility value for each salt.
Slide Number 16 Calculations: Molar solubility	This slide shows how to calculate Molar Solubility for Strontium Phosphate.
Slide Number 17 Calculations: Solubility Product	I have calculated the Molar Solubility and Solubility Product for Strontium Phosphate. Make a data table as shown here in your notebook and fill the columns.
Cursor on the simulation interface.	Increase or decrease the volume of water in the container and observe the results.
Slide Number 18 Assignment I	You can pause the video and do the following: Add more water to the container and observe the dissolved and bound ions in water. Check the solubility of the salts given in the salt drop-down on the right panel.
Slide Number 19 Assignment II	Note the ratio of ions in each salt. Note the number of ions at saturation for each salt.
Click on Design a Salt tab.	Now click on Design a Salt tab at the top of the simulation.
Cursor on the simulation interface.	Here we can creatively design a salt using the different charges for cation and anion.
Cursor on the right panel.	On the right panel using the drop-down buttons select the charges of your choice.
Select cation charge as +2 and anion as -1.	I will select cation charge as +2 and anion as -1.
Select the Solubility Product as 1 x 10-19	I will select the Solubility Product as 1 x 10-19.
Shake the salt dispenser.	Shake the salt dispenser over the container of water.
Cursor on right panel	Observe the ratio of dissolved cations and anions. We see two anions for every one cation. The number of anions is double the number of cations. This ratio is in accordance with the charges we selected for cation and anion for the salt.
Select Solubility Product as 1 x 10-7.	Now increase the Solubility Product of the salt to 1x10-7.
Shake the salt dispenser over the container of water.	Shake the salt dispenser over the container of water. Observe the number of dissolved ions in the right panel.
Cursor on the right panel.	Notice the solubility of the salt. The number of dissolved ions is more this time. Hence, solubility is more when Solubility Product value is more.
Slide Number 20 Summary	Let us summarize. In this tutorial we have learnt about, Solubility of different salts Created a neutral compound from anions and cations Equilibrium expression for dissolution of salt in water.
Slide Number 21 Summary	Calculated the molarity of solutions Calculated Solubility Product of salts Application of Le Chatelier's principle to the dissolution of salts
Slide Number 22 Summary	Designed a salt with various combinations of charges and Solubility Products. Used Solubility Product values to predict solubility.
Slide Number 23 Assignment	As an assignment, Explore more salts with various combinations of charges and Solubility Products.
Slide Number 24 Assignment Show table 2.2	As an assignment, Calculate the Molar Solubility and Solubility Product for the salts.
Slide Number 25 About Spoken Tutorial Project	The video at the following link summarises the Spoken Tutorial project. Please download and watch it.
Slide Number 26 Spoken tutorial workshops	We conduct workshops using spoken tutorials and give certificates. For more details, please contact us.
Slide Number 27 Answers for THIS Spoken Tutorial	Please post your timed queries in this forum.
Slide Number 28 Acknowledgements	Spoken Tutorial project is funded by Ministry of Education (MoE), Govt. of India
Slide Number 29 Thank you	The script for this tutorial is contributed by Snehalatha Kaliappan from IIT Bombay. This is Vidhi Thakur, a FOSSEE summer fellow 2022, IIT Bombay, signing off. Thank you for joining.

Contributors and Content Editors

Madhurig, Nancyvarkey, Vidhithakur